Enhanced photocatalytic activity of a flower-like In2O3/ZnGa2O4:Cr heterojunction composite with long persisting luminescence

Abstract

The development of new photocatalysts with high photocatalytic efficiency and catalytic stability, and long persisting luminescence is critical for ensuring environmental protection and clean energy production. In this study, we develop a flower-like In2O3/ZnGa2O4:Cr heterojunction composite with enhanced ultraviolet (UV) photocatalytic activity using a facile two-step hydrothermal method. The spectral response range of the heterojunction composite is widened to the visible-light range owing to the presence of the ZnGa2O4:Cr persistent luminescence nanoparticles with sizes of less than 10 nm. The heterojunction composite is dispersed on the flower petals of In2O3. The In2O3/ZnGa2O4:Cr/1:1 composite exhibits photo-degradation performance for rhodamine B degradation that is superior to those of pure In2O3, ZnGa2O4:Cr, In2O3/ZnGa2O4:Cr/1:0.5 and In2O3/ZnGa2O4:Cr/1:2, achieving complete degradation after 80 min under UV light irradiation. Moreover, it exhibits long afterglow luminescence that lasts for more than 72 h. Thus, the In2O3/ZnGa2O4:Cr/1:1 composite shows great potential for use in round-the-clock photocatalytic applications.